Astronomers created the deepest map of the distribution of matter in the universe


UNITED STATES (VOP TODAY NEWS) – Astronomers have created the deepest of the three-dimensional maps of the distribution of matter, covering a vast part of the sky. Let us clarify that depth means the maximum distance from the Earth that the map covers. The data will help to better understand the nature of dark matter and dark energy .

The achievement is described in a scientific article, the preprint of which is published on the website by a group led by Shiang-Yu Wang from the FLATYRON Institute in the USA.

The review was called Hyper Suprime-Cam (HSC), which can be roughly translated as “super-high camera”. It is performed on a Subaru telescope located in Hawaii. The map was compiled according to the first year of observations calculated for five years.

The researchers were interested in gravitational lensing of distant galaxies. Let us explain what we are talking about. According to the general theory of relativity , the gravitational field is a curvature of space-time. Because of it, a ray of light passing near a massive object changes its trajectory. The body works like a lens, focusing the radiation of a distant object.

This effect has been repeatedly tested and widely used by astronomers. For example, it allows you to see very distant objects, focusing the light from them and actually working as a telescope. This is how the most remote of the observed planets and a single star were discovered.

In addition, studying the light collected by such a “telescope”, it is possible to establish how its focusing mass is distributed in space. This is what researchers were interested in. It is important that the method “detects” both ordinary matter and dark matter.

Astronomers obtained images of ten million galaxies subjected to gravitational lensing. Observed in the sky playground was 137 square degrees. According to this data, they compiled a three-dimensional map of the distribution of matter.

This is not the first map covering a similar or even large area in the sky, but HSC differs from such analogues in its depth. Previous reviews of this type concerned only the nearest (on a cosmological scale) neighborhoods of the Galaxy.

The authors compared their results with the predictions made using the Planck space telescope observing the CMB. The universe according to HSC was somewhat more homogeneous. But a rigorous statistical analysis has shown that this difference is within the bounds of the inevitable measurement error.

One of the main applications of their work, the authors see a refinement of the nature of dark energy. VOP described in detail about this substance, thanks to which the universe expands with acceleration.

“Our map gives us a better idea of ​​how much dark energy there is, and tells us a little more about its properties and how it accelerates the expansion of the Universe,” explains co-author Rachel Mandelbaum of Carnegie Mellon University. “HSC is a great addition to other research. Combining data from [several] projects will be a powerful tool with which we will try to more and more clarify the nature of dark matter and dark energy.”

The full data of the five-year review will cover several times a larger portion of the celestial sphere and will give even more food for thought to cosmologists. In addition, they are planned to be used to study the evolution of galaxies, outbreaks of supernovae and other variable objects, and our own Milky Way.